In recent years, in a material analysis field, an effect by a specimen segment (Hereinafter, referred to as a specimen segment.) it for an electron microscope such as a transmission electron microscope (TEM) being exposed to atmosphere is discussed (an effect by oxidization caused by atmosphere, or adsorption of a slight amount of materials existing in atmosphere etc.). Therefore, an importance is began to be recognized that a specimen segment should be transferred to an electron microscope such as a transmission electron microscope (TEM) without a specimen being exposed to atmosphere to conduct an observation by TEM.
For example, in a holder for TEM, in particular, a transport holder for shielding atmosphere (Hereinafter, referred to as a transfer holder) is a holder wherein a seat portion for fixing a specimen segment is stored into an external cylinder portion of the holder to keep away the specimen from an outside air environment. Usually, an O-ring contacts with an inside surface of a support portion for supporting a specimen holder to be used with the aim of sealing air-tightly between the support portion and the specimen holder (Patent literature 1).